ISSN 2996-8215
International Journal of Cardiology | Vol. 1, No. 9, September 2010 | pp. 65–72
DOI: 10.46882/2010/IJC/000018
Original Research Article
Prevalence and Prognostic Significance of Subclinical Right Ventricular Dysfunction in Primary Pulmonary Hypertension
Sarah E. Lawson¹, David R. Morris¹, Grace K. Thompson²
¹Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
²Department of Cardiology, Royal Edinburgh Hospital, Edinburgh, United Kingdom
Abstract:
Right ventricular (RV) function is a critical determinant of survival in patients with primary pulmonary hypertension (PPH). However, early or subclinical RV dysfunction can be difficult to quantify using standard echocardiographic metrics. This study assessed the prevalence of subclinical RV impairment using speckle-tracking echocardiography derived longitudinal strain and investigated its association with clinical worsening over a 3-year follow-up period. We prospectively evaluated 95 PPH patients with preserved conventional RV ejection fraction (RVEF greater than or equal to 45%) and 40 healthy controls. RV free-wall longitudinal strain (RV-FWS) was analyzed off-line. Clinical worsening was defined as a composite of hospitalization for heart failure, lung transplantation, or death. Mild PPH patients exhibited significantly impaired RV-FWS compared to healthy controls (-18.2% ± 2.4% vs. -25.6% ± 2.1%, p < 0.001), revealing a 42.1% prevalence of subclinical RV dysfunction despite normal RVEF. Over a median follow-up of 34 months, 28 patients (29.5%) experienced clinical worsening. Kaplan-Meier survival curves demonstrated that patients with an absolute RV-FWS less than 18% had a significantly higher rate of clinical events compared to those with a strain greater than or equal to 18% (log-rank p = 0.004). Cox proportional hazards analysis confirmed that impaired RV-FWS was an independent predictor of long-term clinical worsening (hazard ratio: 1.45 per 3% decrease, 95% CI: 1.15–1.83, p = 0.002). Subclinical right ventricular dysfunction is highly prevalent in PPH patients with preserved conventional ejection fractions and represents a strong, independent predictor of poor clinical progression.
Keywords: Primary pulmonary hypertension, Right ventricular dysfunction, Speckle-tracking echocardiography, Longitudinal strain, Prognosis
Received: June 05, 2010; Revised: July 18, 2010; Accepted: August 11, 2010; Published: September 15, 2010
Citation: International Journal of Cardiology, 2010, Vol. 1, No. 9, pp. 65–72, DOI: 10.46882/2010/IJC/000018